1G 1g head - metal half moon seal too small?

[athlete3344]

I was attempting to install the evo half moon seal in a 1g head and it doesnt fit by ~ half a mil. Measured head width as 8.7 +/- 0.1-0.2 mm with some wider spots. Inner width of the seal was closer to 8.4-8.5mm. When installing it, I put Threebond 1207 on the inner race of the seal and the corners. After tapping it pretty good with a wood block, it sat proud of the valve gasket surface by probably 1/8". I lightly sanded the exterior of the head a bit, and it seemed like it wanted to fit a bit better but never really fit correctly.

Have a new seal on the way since the old one got pretty marred up when removing it, maybe I just had a bad casting or something.

In case the next one has similar measurements, what would the correct path forward being to get it to fit up right? I figure the 2 options I have would be to remove material from the exterior side of the head, or remove material from the seal.

Thanks!

 

[pauleyman]

I was attempting to install the evo half moon seal in a 1g head and it doesnt fit by ~ half a mil. Measured head width as 8.7 +/- 0.1-0.2 mm with some wider spots. Inner width of the seal was closer to 8.4-8.5mm. When installing it, I put Threebond 1207 on the inner race of the seal and the corners. After tapping it pretty good with a wood block, it sat proud of the valve gasket surface by probably 1/8". I lightly sanded the exterior of the head a bit, and it seemed like it wanted to fit a bit better but never really fit correctly.

Have a new seal on the way since the old one got pretty marred up when removing it, maybe I just had a bad casting or something.

In case the next one has similar measurements, what would the correct path forward being to get it to fit up right? I figure the 2 options I have would be to remove material from the exterior side of the head, or remove material from the seal.

Thanks!

Is this an OEM metal half moon? They will generally sit a little proud in my experience but not 1/8". If you push it down with your thumb where does it sit?

 

[athlete3344]

Yup, OEM. Honestly, I could barely push it down into the groove to get it started. It took several harder taps w a block of wood and hammer to get it moving.

 

[pauleyman]

I would just get another or use the rubber one.

 

[19Eclipse90]

The rubber ones measure about 8.5-8.6 mm (I actually measured 8.55-8.56mm) and, obviously, will stretch a little bit if needed. I probably have a metal 4G63 half moon somewhere but I could end up looking all night for it and never find it until Saturday.

FWIW, I have a metal half moon from a 420A (part number M04667731 or just 04667731), it measures about 8.3mm, definitely doesn’t fit the 4G63 head. Could easily be mistaken for the 4G63 seal without measuring.

 

[athlete3344]

Whenever the new one shows up ill take some pics w/ measurements and ill see if i can find where I tossed the last one.